Return bend



Oct. 28, T CLARKE I v I RETURN BEND Filed March 7 1945 Fiyure 1 Invenior Thomas H- CZ arke flt iorne Patented st. 28, 1947 RETURN BEND 7 Thomas H. Clarke, Philadelphia, Pa., assignor to The Atlantic Refining Company, Philadelphia Pa., a corporation of Pennsylvania Application March 7, 1945, Serial No. 581,463

The invention relates to improvements in removable return bends used for connecting furnace tubes and the like in such situations where it may be desirable to connect the adjacent ends of parallel tubes in order to provide a continuous passageway for fluids,

The main problem connected with the use of such return bends, as have heretofore been known in the art, has been that of obtaining a satisfactory joint or seal between the tubes and the bend. As the liquids orgases passing through the tubes are often at high temperature and pressure it is imperative that such joint be adapted to withstand such temperature and pressure without permitting leakage. To accomplish the desired result the joint must be constructed in such a manner as to permit either even or uneven expansion of the tube and the bend. 7

Further, where a decomposable substance such as hydrocarbon oil is heated in the tube, the oil frequently decomposes and tends to form a solid deposit on the interior of'such tube. Therefore, a joint to be practical must readily permit cleaning the interior of the tube.

An object of the invention is to provide a joint or seal between a return bend and the parallel tubes that it connects which will permit either even or uneven expansion either of the tubes themselves or of the tubes and the bend without leakage. Such joint has a certain flexibility in the movement of the integral parts thereof, which results in increased efficiency over the devices which are known in the art.

Another object of the invention is to provide a joint between a return bend and the parallel tubes that it connects which will remain sealed under operatin conditions lIlVOlVll'lg high temperature and pressure.

A further object of the invention is to provide a joint which is easily assembled and will not hinder the removal of the return bend for purposes of cleaning or the like.

Other objects of the invention will be readily apparent from the description and claims which follow.

Referring now to the drawing, in which like numerals are used to designate like parts:

Figure 1 is a View of the invention in vertical crOss section;

Figure 2 is a top plan view of Figure 1.

Referring now to the drawing, I and 2 are parallel tubes which are welded, or attached by other suitable means as at 3 to collars 4. A portion of the walls of collars 4 are cut away as at 5 to facilitate the insertion of the U-shaped re- 6 Claims. (01. 285-20) turn bend 6. The lower portions of collars 4 are provided with internal downwardly beveled seats 1. Such seats are adapted to receive a gasket 8 of circular cross section which is designed to form a seal between collars 4 and the downwardly and inwardly tapered ends l8 of return bend 6.

The upper portions of collars 4 are provided with internal threads 9. A cap member ID is recessed at H to receive the upper end of collar 4. A second and similar cap (not shown) is provided for the other collar 4. The inner surface of recess II is threaded at I2 to coact with the internal thread 9 on collars 4.

While this method of connecting cap [0 to collar 4 is preferable, it will be manifest that other methods may be used, for example, external rather than internal threads may be formed on collar 4. In such case coacting threads would, of

course, be provided on the outer surface of re-.

cess II of cap [0.

The cap IE! is provided with a threaded opening l3 through which extends a screw l4, the lower end of said screw being crowned as at 15 and adapted to engage the flat shoulder l E on the return bend 5. The upper end of screw i4 is provided with a head I1 or other suitable means whereby such screw may be rotated and pressure thereby applied to the return bend 6 to effect the desired seal between the bend, the gasket 8, and the collar 4,

The operation of the invention is as follows:

After the collars 4 have been attached to the tubes I and 2, the gaskets 8 are disposed on the internal seats I of the collars 4. The U-shaped bend is then inserted until the beveled ends l8 rest upon the gaskets. The caps in are screwed down on the collars 4 and pressure is brought to bear upon the U-shaped bend by taking up on screws l4, thereby forming a seal between the beveled ends l8 of the bend, the gasket 8, and the seats 1 of the collars 4.

An advantage of the invention resides in the use of gaskets of circular cross section between two downwardly beveled seats rather than between flat surfaces or ground joints as have heretofore been commonly employed. By combining the beveled edges with gaskets of this type, a slight rolling or slipping movement is obtained when the pressure is applied to the U-shaped return bend, serving to wedge the gasket more firmly into place, thus creating a perfect seal with a minimum of damage or wear to the parts involved. This is in direct contrast to the ordinary ground joint in which, under the application of any pressure, a grinding movement results which will eventually necessitate the replacement of the parts involved. Further, under extreme pressures the gasket has a slight tendency to flatten out at the points of contact, thereby doubly insuring a perfect seal.

The example here given and the particular description set forth are merely presented in order to illustrate how the invention may be app ied. Other forms and variations coming within the scope of the appended claims will readily suggest themselves to those skilled in the art.

I claim:

1. A device for connecting tubes to provide a continuous passageway therethrough, comprise ing collar members attached. to the adjacent ends. of said tubes, the walls of said collar membersbeing recessed to accommodate a U-shaped return bend, internal threads upon the upper sections of said collar members, downwardly beveled.

seats internally of said collar members, a U- shaped return bend having downwardly and inwardly beveled ends, gaskets of circular crosssection interposed betweenthe. internal seats of the collar members and the beveled ends. of the bend, cap members threaded to the upper section of said collar members, threaded openings axially of said cap members, and bolt members threaded through said axial openings of said cap members for maintaining the beveled ends of said bend in contact with said gaskets.

2. A device for connecting the adjacent ends of parallel tubes to provide a continuous passageway therethrough, comprising collar members attached to the ends of said tubes, the Walls of said collar members being. recessed, internal threads upon the upper section of such collar members, downwardly beveled seats internally of said collar members, a, U-shaped return. bend having downwardly and inwardly beveled ends inserted into the collar members through the aforementioned recesses, gaskets of circular cross section interposed between the internal seats of the collar members. and the beveled ends of the bend, ca members. having circular recesses formed therein to accommodate the ends of the collar members, threads provided on the inner wall of the recess and adapted to coact with the internal threads on the collar members, threaded openings axially of said cap. members, and bolt members threaded through said axial. openings of said cap members for maintaining the beveled ends of said bend in contact with said gaskets.

3. Means for connecting the ends of two parallel tubes to provide a continuous passageway therethrough comprising collar means fixedly secured to the ends of said tubes, said collar means being recessed adjacent the tube ends to accommodate the ends of asubstantially U-shaped re.- turn bend, and at the opposite. ends thereof being provided with internal threads, said recesses. being terminated so as to provide downwardly, in.- wardly extending seat members, the ends of said substantially U-shaped return bend being bevelled complementary to said seat members, and means engageable with said internal threads and with said substantially U-shaped return bend for securing the ends. of said substantially Ll-shaped return bend relative to said seat. members.

4. Means for connecting the ends of two parallel tubes to provide a continuous passageway therethrough comprising collar means fixedly secured to the ends of said tubes, said collar means being recessed adjacent the tube ends to accommodate the ends of a substantially U-shaped return bend, and at the opposite ends thereof being provided with internal threads, said recesses being terminated so as to provide downwardly, inwardly extending seat members, the ends of said substantially U-shaped return bend being bevelled complementary to said seat members, sealing means positioned on said seat members adjacent the ends of said return bend, and means engageable With said internal threads and with said substantially U-shaped return bend for maintaining the ends of said return bend relative to said seat members.

5. Means for connecting the ends of two parallel tubes to provide a continuous passageway therethrough comprising collar means fixedly secured to the ends of said tubes, said collar means being recessed adjacent the tube ends to accommodate the ends of a substantially U-shaped re.- turn bend, and at the opposite ends thereof being provided with internal threads, said recesses being terminated so as to provide. downwardly, inwardly extending, seat members, the ends of said substantially U-shaped return bend being bevelled complementary to said seat members, circular crossesectional gaskets. positioned on. said seat members adjacent the ends. of said return bend, cap. members threaded to the internal threads provided on said collar members, threaded openings axially of said cap members, and bolt members threaded through said openings for bringing the ends. of said return bend into sealing relationship With said gaskets.

6. In combination with a U-shaped return bend adapted to provide a continuous passageway between two parallel tubes, collar means aflixed to the adjacent ends of said tubes, said collar means being internally recessed adjacent the tube ends to accommodate the ends of said return bend, downwardly and inwardly extending seat members within said recesses the ends of said return e d ngb v lled comp emen ry he e o, circular cross-sectional gaskets interposed between said seat members and the bevelled ends, of said r n ben ap m ber h v n c ular 7 ce es f rm d th rein to a comm dat t e n s of said collar means and affixed to said collar means, threaded openings axially of said cap members, and bolt members threaded through aid p in n c nta ing sai r urn b nd apt d to main ain the n s of s i re u n end in s alin r ation h p wit aid gaske s.-

THOMAS H.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,046,155 Fantz June 30, 1936 1,563,836 Conn Dec, l, 1925 

